Effect of light at night on molt pattern.

<p>We scored the molt condition (0 = no molt, 5 = completed molt) for the ten primary and the first six secondary flight feathers. In the first experimental year (A), molt was measured between April and December (x-axis). Control birds (blue) experienced dark nights, while experimental birds (red) were exposed to constant light of 0.3 lux at night. Triangles and dashed lines depict urban birds, circles and solid lines depict rural birds. Each symbol represents the sum of molt scores for all feathers of each individual, averaged over all individuals of one group. Error bars represent SEM. Six experimental birds, three rural and three urban, did not finish to molt. In the second experimental year (B), we checked molt only once, on August 13^th. Vertical bars represent the molt score for each feather, averaged over all individuals of one group. Blue bars (left) depict control birds, red bars (right) depict experimental birds. Within each treatment group, blank bars represent urban birds, filled bars represent rural birds. Error bars represent SEM. For details of experimental set-up see Methods and Figure 1.